The invention relates to a danger alarm system utilizing a plurality of alarm devices which are connected to a central exchange over call circuits, whereby the state of the individual alarms can be sampled in the central exchange by means of test control units and can be evaluated for the formation of an alarm or trouble signal by means of an evaluation installation.
Such alarm systems are known, for example, in a form of public or private auxiliary alarm systems and in general, such systems are modularly designed, whereby a plurality of lines can usually be connected to the switching component groups in the central exchange, and a plurality of fire alarms connected to each line. It is possible, by means of so-called chain synchronization, to transmit the data of the individual alarm devices, in analog form, on a common line. See for example German O.S. No. 2,641,489. In such systems, it is also necessary to properly further process the information received from the alarm devices actually switched on and to insure that the system components are not switched on and do not produce interference, and that each and every change in the system configuration is recognized.
In traditional systems, the relaying of the alarm information was transmitted over special classification lines which, on demand, had to be interrupted. In addition, it was also customary to simulate system parts that did not exist, i.e. to simulate an operable interface by means of a special terminal element. Operations of this type were manually performed in the system usually utilizing screwdrivers or soldering irons. Such activity involves a great deal of working time and is always subject to the danger that lines can be mistaken and incorrectly connected.
The invention has among its objects the creation of a danger alarm system, of the type initially referred to, in which such classifications in wiring are not required. Constant monitoring of the alarm configuration should be guaranteed, identification of the alarm devices which are connected to a common line, as well as to enable an evaluation of different types of alarm systems within the same lines, should be provided, and further, desired changes in the alarm configuration should be achieved in a simple manner.
These objectives are achieved, in accordance with the invention, by the provision of a memory in the central exchange, in which, for each of the arm devices connectable in the system, the seizure data as well as various data characteristic of the respective alarms is stored. A line sampling installation is provided by means of which the individual alarm lines can be cyclically sampled, and by means of which the alarm data arriving from the individual lines can be supplied to a cooperable evaluation installation. In addition, a memory sampling installation is provided by means of which, upon each step of the line sampling installation, the storage locations for all alarms connected to the line involved can be interrogated, whereby the memory content is supplied to the evaluation installation for the formation of rated values. The evaluation installation is also provided with a comparison installation in which the data arriving from the individual alarm lines can be compared with the rated values formed from the stored data and can be processed for the formation of trouble or alarm signals if required.
In accordance with the invention, the memory provided in the central exchange thus contains data relating to the plurality of connected alarm lines, as well as relating to the plurality of alarm devices associated with each line, which memory locations can be entered either over input means, for example a key board, or automatically by means of a microcomputer. At the beginning of the operation system, a test can be carried out, for example, to see whether or not a line is connected, as well as to see how many alarm devices per line are connected. It is thereby possible to ascertain whether the individual alarm devices are in a quiescent, an alarm, or a disrupted condition.
In addition, it is possible to group individual alarms together in predetermined groups independent of the actual position on the alarm line, for example, grouping of alarm devices of the same type which either spatially belong together, or are to be processed according to the same evaluation criteria. Thus, it is possible to intentionally cause all similar alarms, for example, smoke alarms, of the system to respond and enter the common criterium, i.e. "smoke alarm" into the memory for all addressed alarm devices, by means of a suitable command. During the memory sampling, this alarm criterium is then supplied and correspondingly taken into consideration during the rated value formation.
All information which represents the actual condition of the alarm configuration, and stored in the system, can be supplied over a dialogue terminal for comparison with the desired rated condition. As soon as the actual condition for a part of the system or for the entire system has been determined to be free of error and entered, the system can be placed in operation by means of a corresponding switch, whereby the rated condition is the actual condition, and all deviations therefrom will thereafter be recognized as trouble.
Expediently, a microprocessor can be employed for control of the line sampling installation, of the memory sampling installation and of the evaluation installation which microprocessor is connected with a corresponding memory as well as with an input installation and an output installation.